Inverters are now used in various electrical apparatuses such as hybrid electric vehicles (HEVs) and electric vehicles (EVs). The use of inverters in these applications has been increasing every year because of the recent environmental issues and energy saving promotion. And, today's inverters require high power, low power consumption and small size, and therefore technologies such as high voltage inverter circuits and high density mounting techniques are being developed.
Inverters mainly include: power modules having mounted therein power semiconductor devices (such as insulated gate bipolar transistors (IGBTs)); capacitors; coils; other components; and power distribution mounting components (often referred to as busbars) for carrying high currents inside the inverter. FIGS. 10 and 11 are schematic illustrations showing longitudinal sectional views of conventional power distribution mounting components used in inverters.
As illustrated in FIG. 10, in the conventional power distribution mounting component (hereinafter “busbar”) 112, an insulating layer 102 (e.g. an insulator plate, paper or film) is interposed between thick conductors 100 of a metal (such as copper and aluminum), thereby providing insulation between the thick conductors 100. In FIG. 11, an adhesive layer 103 is formed on at least one surface of the insulating layer 102 and provides adhesion between the insulating layer 102 and the overlying thick conductor 100, and this insulating layer 102 with the at least one adhesive layer 103 provides insulation between the thick conductors 100. This is a more typical structure of conventional busbars (see, e.g., Patent Literature 1).